Good morning people!! My name's Andrey Vieira. I am a PhD student in Belém -
Brazil (amazon) in the area of energy systems at PPGEE-UFPA. I intend to
develop my thesis in the area of optimization for restoration of electric
energy distribution systems with some goals and restrictions. My purpose is to
develop an intelligent algorithm that performs a configuration in Electric
Power Distribution Systems for the problem of restoration in both literature
feeders and in the most complex (real), three-phase and unbalanced radial, with
a multiobjective approach and with time requirements real.
I have read several papers on the subject and intend to use MATPOWER to
optimize the reconfiguration on some IEEE feeders (16,33 and 84 bars).
Currently, I am starting programming and I have come up against a simple
question regarding the manipulation of the (normally open and normally closed)
IEEE cases of matlab (case33, case69, case84, etc), ie: How to manipulate the
(Normally closed sections) and those to be closed for analysis (TIE keys)?
Anyway, the reason for my contact is to know if anyone can help me regarding
the switchings in the MATPOWER IEEE case files. That is, how do I manipulate
(change the state of the keys)? For example, in the case of 33 bars, in the
initial configuration, TIE keys are part of the initial configuration of the
system. I do not know if I'm getting it wrong, but when running load (runpf
('case33')), whether or not you have the 5 TIE keys inserted in the case33
files, the result is always the same. I know I must be making a mistake, I just
do not know what it is. I would appreciate the help.
"A Segurança econômica não se encontra no emprego, mas sim em seu próprio poder
de produzir - pensar, criar, aprender, adaptar. Esta é a verdadeira
independência financeira, e não a posse de riquezas. É ter poder para produzir
riquezas. É algo interno"
(Stephen Covey).
________________________________
De: bounce-121060554-77188...@list.cornell.edu
<bounce-121060554-77188...@list.cornell.edu> em nome de Ray Bo
<rbo2...@gmail.com>
Enviado: terça-feira, 6 de dezembro de 2016 07:35
Para: MATPOWER discussion forum
Assunto: Re: state estimation: active power not balanced in test cases
Hi Ray,
Sure I will take care of it.
Niccolò,
As I don't have 6.02b2 right now, I did a quick check on v5.1, and did see
the issue you brought up. The state estimation results are actually
correctly presented in the last section of the screen output, where you can
see the Pg2=0.3034 pu, Pg3=0.1336 pu. So the gen, load and losses are
balanced. The Pg2 and Pg3 values you see in the 'Generator Data' output
section are actually the default values from the 3-bus case, and appear to
be inbalanced with load. The reason Pg2 and Pg3 values do not get updated in
the 'Generator Data' output section is that, to output the power flow
solution in a nice format, I simply took advantage of the MATPOWER function
'pfsoln' to update bus, gen, branch data structures to match power flow
solution. This function however only updates Pg for the slack bus generator
and not for the rest of the generators (because those are PQ and PV buses
and there is no need to do it).
To clean up the output to avoid such confusion, I have implemented a quick
fix for the issue by updating the Pg and Qg using state estimation results.
The code with the quick fix is attached. I haven't tested it extensively.
Please use it and let me know if you find it useful or if you have
additional questions. I can be reached at rui...@ieee.org.
Thanks,
Rui
-----Original Message-----
From: Ray Zimmerman
Sent: Monday, December 5, 2016 9:27 AM
To: Rui Bo
Cc: MATPOWER discussion forum
Subject: Re: state estimation: active power not balanced in test cases
Hi Rui and Niccolò,
The state estimation code was contributed by Rui Bo, so I'm not that
familiar with it. Rui, I was wondering if you might be able to address
Niccolò's questions.
Thanks,
Ray
> On Dec 1, 2016, at 6:20 PM, Niccolò Citroni <niccolo.citr...@gmail.com>
> wrote:
>
> Hallo, I'm new to matpower, using it for my master thesis.
> I'm trying to figure out how the se program works, and running the
> included test cases I noticed the following:
> there is a big unbalance in active power in the network, for example in
> the 3 bus case there are more than 380 MW of active power in excess,
> considering generation, load, and losses. How is that possible?
> Another thing: modifing the load i get different results runnning the se.
> Why is that? shouldn't the state estimation be based only on the input
> mesurements and the topology of the network? How has the load and
> generator power anything to do with the se, when not included in the
> mesurements? From what I know the power balance at each node should be a
> result of the se, not part of the input data (when not as mesurements of
> course).
> I hope I've been clear enough.
> I'm using version 6.0b2
> Thankyou for the help and the program.
> Niccolò Citroni
